Re: [PATCH 4/8] x86, mce: rename bootparam parser

Hidetoshi Seto
2011-06-20T04:48:58Z

(2011/06/18 17:38), Borislav Petkov wrote:
> On Fri, Jun 17, 2011 at 03:25:51PM -0700, Luck, Tony wrote:
>>> and leave this like this. "nomce" is the same as "mce=off" and frankly,
>>> I'd like to remove this redundancy, thus no need to do the code
>>> relocation. In addition, I don't think there are lots of systems running
>>> with "nomce" so I really think we should drop it.
>>>
>>> So Ingo, hpa, what is the proper way to remove early setup params? Maybe
>>> through Documentation/feature-removal-schedule.txt?
>>
>> Though it seems odd to me that anyone would want to turn mce off,
>> the fact that we have two ways to do so would indicate that people
>> do (or at least did) want to do this.
>
> Yeah, the only usecase I could think of for this is people doing their
> own userspace DRAM ECC evaluation like google. But they'd still need to
> have an #MC handler... or they could parse syslog for the output from
> the default unexpected_machine_check().. hm.
>
>> It seems like we'd need a long "deprecated" period (till all the
>> major OSVs turn out a new release) to remove this without surprises.
>> If the "nomce" option just disappears, then people using it will
>> not realize that their boot time argument was ignored (until they
>> see a reported error).
>
> Yeah, we could do a grace period with a warning:
>
> /*
> * Old style boot options parsing. Only for compatibility.
> */
> static int __init mcheck_disable(char *str)
> {
> pr_err("\"nomce\" boot param is deprecated. Please use \"mce=off\"\n");
>
> mce_disabled = 1;
> return 1;
> }
> __setup("nomce", mcheck_disable);
>
> and then kill it.

Thank you for giving a new direction!
I'll write a patch to "deprecate nomce" instead of this rename/cleanup.

Thanks,
H.Seto